丝绸之路的开通使得古代中外交通一直比较频繁。丝绸之路选择沿祁连山麓延伸,其最主要的原因是 A.该地区的地势平缓,易于行走 B.该地区气候暖湿,自然条件优越 C.该地区有祁连山冰雪融水形成的地下水,提供了水源 D.该地区人类开发较早,经济发达 答案:C. The little girl _______ reading her favourite book alone under the tree, while the rest _________ talking excitedly about their trip. A. was, was B. was, were C. were, was D. were, were